For example, in IGCC (Integrated Gasification Combined Cycle) with CO2 capture, as shown in FIG. 7, coal gas produced by gasification in a gasifier 101 is desulfurized in desulfurization equipment 102 and is then fed to hydrogen production equipment 103. This hydrogen production equipment 103 allows the coal gas to react with steam in the presence of a catalyst to transform carbon monoxide contained in the coal gas into carbon dioxide, thus producing hydrogen-rich coal gas. The coal gas after the shift reaction is fed to carbon dioxide capture equipment 104 to capture carbon dioxide from the gas, and the hydrogen-enriched purified gas is fed to power generation equipment 105. In the power generation equipment 105, the purified gas is fed to a combustor of a gas turbine and is used to power the gas turbine.
In the above hydrogen production equipment 103, carbon monoxide (CO) contained in the coal gas is converted into carbon dioxide by adding steam as a shift catalyst. This reaction formula is as represented by formula (I) below:{Math. 1}CO+H2OCO2+H2+40.9 kJ/mol  (1)
Because the shift reaction can be increasingly promoted as a larger amount of steam serving as a shift catalyst is added, the hydrogen production equipment 103 is preferably supplied with an amount of steam sufficient to eliminate carbon monoxide.